Existing communication technology presents a number of communication possibilities, particularly using circuit-switched fixed networks, wireless radio networks and packet-oriented data networks, such as LAN (Local Area Networks) or WAN (Wide Area Networks).
To utilize this variety of communication possibilities, a typical user has up until now mostly used separate terminal devices. Usually, these are a mobile terminal device for connecting to a radio network, a stationary telephone terminal for connecting to a circuit-switched, generally public, telephone network, a personal computer for connecting to a packet-oriented data network and occasionally an IP (Internet Protocol) telephone for packet-based telephony via a data network.
However, the use of separate terminal devices in each case makes a terminal-overlapping integration of communication services more difficult and also involves higher procurement costs.